The long range of this project is to achieve an understanding of how hormones regulate normall genital tract development and how hormones elicit teratogenic effects. Particular emphasis is directed towards the role of epithelial-mesenchymal (E-M) interactions in hormone-induced epithelial development. In order to understand the adverse effects of exogenous estrogens on the development and differentiation of the human fetal genital tract, the ontogeny of estrogen (and progesterone), receptors will be assessed by autoradiography and immunocytochemistry. The effects of DES on the developing human prostate will be examined to determine whether DES causes irreversible changes in the expression of prostate-specific secretory markers (prostatic acid phosphatase, prostate specific antigen and peanut lectin binding sites). This project will entail an examination of the normal ontogeny of expression of these substances and their hormonal control. The abnormalities of ductal morphogenesis elicited by DES will be examined to determine whether DES perturbs the spatial pattern of epithelial DNA synthetic activity. Utilizing animal models, the role of epithelium in myometrial differentiation will be examined to determined whether only uterine epithelium can induce myometrial differentiation or whether other epithelium can induce uterine mesenchyme. The mechanism of epithelial effects on myometrial development will be assessed through use of transfilter culture assemblies in which epithelium and mesenchyme are grown on opposites sides of Nucleopore filters. The role of mesenchymal migration in myometrial differentiation will be assessed by microinjection of vitally dyed mesenchymal cells into the space between epithelium and mesenchyme. Finally, the last aspect of myometrial development will be to determine whether the DES- induced disruption of myometrial differentiation is due to direct estrogen receptor mediated events or via indirect, neuroendocrine imbalance, such as hyperprolactinemia. Utilizing uterine and vaginal epithelial inductions as model systems, the mechanism of these E-M interactions will be examined using transfilter protocols. This project utilizes antibodies to a cell surface heparan sulfate proteoglycan, cytokeratins, epithelial estrogen receptors, and new monoclonal antibodies as differentiation marker probes to assess the effects of mesenchyme on epithelial differentiation. Finally, the development of Mullerian (MD) and Wolffian duct (WD) epithelia will be examined to determined whether Mullerian Inhibiting Substance acts directly on the epithelium or via the surrounding mesenchyme. During the process of MD regression we will determine whether epthelial cells transform into fibroblasts. Lastly, cell attachment and spreading of MD and WD's will be examined to determine the types of extracellular matrix molecules (ECM) that are involved in these processes, to assess the role of hormones on attachment behavior, and to determine whether hormone-induced changes in epithelial attachment is due to direct or mesenchymally regualted processes.